CHR has mild to moderate globally distributed neuropsychological performance deficits that lie between FEP and HCs. Neuropsychological performance deficits are greater in CHR-P than in CHR-NP, but they overlap, reducing their current utility for risk stratification.

IMPORTANCEThe in vivo effect of pilocarpine hydrochloride on the Schlemm canal may help explain its pharmacologic mechanism of action and better indicate its clinical use.OBJECTIVE To investigate the effect of pilocarpine on the structure of the Schlemm canal in vivo in healthy eyes and eyes with glaucoma. DESIGN, SETTING, AND PARTICIPANTSIn this case-control study, healthy individuals and patients with open-angle glaucoma were prospectively enrolled between September 1, 2013, and June 30, 2014, after a complete ophthalmologic examination at a tertiary glaucoma referral practice. Eighty-one serial, horizontal, enhanced depth imaging optical coherence tomographic B-scans (interval between B-scans, approximately 35 μm) of the nasal corneoscleral limbus were performed before and 1 hour after topical administration of pilocarpine, 1%, in 1 eye of healthy volunteers and pilocarpine, 2%, in 1 eye of patients with glaucoma. Fifty B-scans in the overlapping area (circumferential length, approximately 1.7 mm) between the 2 sets of serial scans (before and after pilocarpine administration) were selected for analysis based on the structures of aqueous and blood vessels as landmarks. The cross-sectional area of the Schlemm canal was measured in each selected B-scan. Volume of the Schlemm canal was calculated using commercially available 3-dimensional reconstruction software. MAIN OUTCOMES AND MEASURES Mean cross-sectional area of the Schlemm canal.RESULTS Enhanced depth imaging optical coherence tomographic scans of the Schlemm canal were performed successfully before and after administration of pilocarpine, 1%, in 9 healthy eyes (9 individuals) and pilocarpine, 2%, in 10 eyes with glaucoma (10 patients) (mean [SD] age, 31.9 [7.8] and 68.7 [13.2] years, respectively). Following pilocarpine administration, mean (SD) intraocular pressure decreased from 14.3 (1.3) to 13.7 (1.1) mm Hg in healthy eyes (P = .004) and from 17.5 (6.0) to 16.6 (6.1) mm Hg in eyes with glaucoma (P = .01). The mean (SD) cross-sectional area of the Schlemm canal increased by 21% (4667 [1704] to 5647 [1911] μm 2 ) in healthy eyes (P < .001) and by 24% (3737 [679] to 4619 [692] μm 2 ) in eyes with glaucoma (P < .001) (mean difference in percent increase, 2.2%; 95% CI, -8.5% to 12.9%). The mean (SD) volume of the Schlemm canal in the overlapping area increased from 8 004 000 (2 923 000) to 9 685 000 (3 277 000) μm 3 in healthy eyes (P < .001) and from 6 468 000 (1 170 000) to 7 970 000 (1 199 000) μm 3 in eyes with glaucoma (P < .001).CONCLUSIONS AND RELEVANCE These data suggest that pilocarpine expands the Schlemm canal in eyes with and without glaucoma. No differences in the effect were identified between the 2 groups. Enhanced depth imaging optical coherence tomography may be useful in investigating the effect of pharmacologic agents on the Schlemm canal.

ONHD volume generally correlates with structural and functional optic nerve damage.

Purpose: The coronavirus (COVID-19) pandemic has impacted ophthalmology practices significantly. American Academy of Ophthalmology and Center for Disease Control guidelines suggest mandatory masking of patients and physicians during outpatient visits. We have recently become aware of a mask-induced phenomenon, whereby the intraocular pressure (IOP) as measured by Goldmann applanation tonometry (GAT) is artificially elevated due to mechanical interference from the mask. Clinical Presentation: A 37-year-old male with a history of primary open-angle glaucoma on triple therapy presented for a routine visit. Clinical Findings: When measuring IOP by GAT the right eye measured 16 mm Hg, but the left eye measured 20 mm Hg. The patient’s mask was noted to be touching the base of the sensor rod on the tonometer. This patient’s IOP was falsely elevated due to the lateral edge of his mask touching the base of the applanation tonometer, changing the relationship between the bi-prism tip and the weighted balance below, and eliminating the weighted balance from the pressure measuring mechanism. The patient’s mask was adjusted to ensure there was no touch and repeat measurement showed an IOP of 16 mm Hg in the left eye. Conclusion: Recognizing mask-induced alteration in IOP is essential as it could lead to unnecessary escalation of treatment. We recommend flattening the area of mask protrusion during applanation and ensuring that the sensor arm remains clear of the mask while the tonometer tip approaches the cornea, especially at the moment the mires become visible during corneal contact.